Petroleum refining and petrochemical processes frequently involve slurry hydrocracking. The slurry hydrocracking process produces a pitch fraction that boils above 524° C. and contains organic and inorganic solids. Pitch disposal may be a problem for the refiner if suitable outlets are not available. For example, a typical 40,000 barrel/day slurry hydrocracking unit produces 200,000 tons/year of pitch. As will be appreciated, if a suitable disposal option is not available, the amount of pitched produced by the unit will quickly accumulate.
If the solids are removed from the pitch fraction, the resulting deashed hydrocarbon material can be used for several value-added applications that may include but not limited to fuel oil blending, asphalt manufacturing, and binders for the production of anodes, electrodes, and metallurgical coke. The concentrated solids also become more amenable to further processing, such as combustion, metals reclamation, landfill disposal, and transport to cement plants and other outlets.
One process for separating the pitch fraction into solids and hydrocarbons is a deashing process. Additionally, as mentioned above, one potential application for the deashed pitch is its use as a blending component for the production of asphalt binder for road paving applications. However, deashed pitch is a very stiff and brittle material with zero penetration and very low ductility. Penetration and ductility are two of the key specifications for Viscosity-Graded (VG) asphalt binders for use in pavement construction as detailed in ASTM D3381/D3381M-13. To make acceptable asphalt binders, deashed pitch needs to be blended with a suitable and easily accessible material preferably hydrocarbon with flash points greater than 220° C.
Therefore, it would be desirable to provide a process that produces deashed pitch, and even more desirable to have a process that produces an asphalt binder from the deashed pitch.